Meandering rivers in modern desert basins: Implications for channel planform controls and prevegetation rivers

Autor(es)

Santos, Mauricio G. M. ^[1] ; Hartley, Adrian J. ^[2] ; Mountney, Nigel P. ^[3] ; Peakall, Jeff ^[3] ; Owen, Amanda ^[4] ; Merino, Eder R. ^[5] ; Assine, Mario L. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, CECS, Av Estados 5001, BR-09210580 Santo Andre - Brazil

^[2] Univ Aberdeen, Dept Geol & Petr Geol, Aberdeen AB24 3UE - Scotland

^[3] Univ Leeds, Sch Earth & Environm, Leeds LS2 9JT, W Yorkshire - England

^[4] Univ Glasgow, Sch Geog & Earth Sci, Univ Ave, Glasgow, Lanark - Scotland

^[5] Univ Sao Paulo, Inst Energy & Environm, Av Prof Luciano Gualberto 1289, Cidade Univ, BR-05508010 Sao Paulo - Brazil

^[6] UNESP, Inst Geociencias & Ciencias Exatas, Ave 24A 1515, BR-13506900 Rio Claro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SEDIMENTARY GEOLOGY; v. 385, p. 1-14, MAY 1 2019.
• Citações Web of Science: 3

Resumo

The influence of biotic processes in controlling the development of meandering channels in fluvial systems is controversial. The majority of the depositional history of the Earth's continents was devoid of significant biogeomorphic interactions, particularly those between vegetation and sedimentation processes. The prevailing perspective has been that prevegetation meandering channels rarely developed and that rivers with braided planforms dominated. However, recently acquired data demonstrate that meandering channel planforms are more widely preserved in prevegetation fluvial successions than previously thought. Understanding the role of prevailing fluvial dynamics in non- and poorly vegetated environments must rely on actualistic models derived from presently active rivers developed in sedimentary basins subject to desert-climate settings, the sparsest vegetated regions experiencing active sedimentation on Earth. These systems have fluvial depositional settings that most closely resemble those present in prevegetation (and extra-terrestrial) environments. Here, we present an analysis based on satellite imagery which reveals that rivers with meandering channel planforms are common in modern sedimentary basins in desert settings. Morphometric analysis of meandering fluvial channel behaviour, where vegetation is absent or highly restricted, shows that modern sparsely and non-vegetated meandering rivers occur across a range of slope gradients and basin settings, and possess a broad range of channel and meander-belt dimensions. The importance of meandering rivers in modem desert settings suggests that their abundance is likely underestimated in the prevegetation rock record, and models for recognition of their deposits need to be improved. (C) 2019 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 14/13937-3 - Análise comparativa entre depósitos de sistemas fluviais modernos e do registro geológico: desenvolvimento de modelos análogos em escala de afloramento para a interpretação paleoambiental de depósitos fluviais
• Beneficiário: Maurício Guerreiro Martinho dos Santos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado